How to use the gcovr.coverage.FileCoverage function in gcovr

return

    if excluded:
        logger.verbose_msg("  Excluding coverage data for file {}", fname)
        return

    key = os.path.normpath(fname)

    parser = GcovParser(key, logger=logger)
    parser.parse_all_lines(
        INPUT,
        exclude_unreachable_branches=options.exclude_unreachable_branches,
        exclude_throw_branches=options.exclude_throw_branches,
        ignore_parse_errors=options.gcov_ignore_parse_errors)

    covdata.setdefault(key, FileCoverage(key)).update(parser.coverage)

    INPUT.close()

def _split_coverage_results(covdata, coverages):
    for coverage in coverages.values():
        if coverage.filename not in covdata:
            covdata[coverage.filename] = FileCoverage(coverage.filename)

        covdata[coverage.filename].update(coverage)

def __init__(self, fname, logger):
        self.logger = logger
        self.excluding = []
        self.coverage = FileCoverage(fname)
        # self.first_record = True
        self.fname = fname
        self.lineno = 0
        self.last_code_line = ""
        self.last_code_lineno = 0
        self.last_code_line_excluded = False
        self.unrecognized_lines = []
        self.deferred_exceptions = []
        self.last_was_specialization_section_marker = False

logger = Logger(options.verbose)

    for filename in filenames:
        gcovr_json_data = {}
        logger.verbose_msg("Processing JSON file: {}", filename)

        with open(filename, 'r') as json_file:
            gcovr_json_data = json.load(json_file)

        assert gcovr_json_data['gcovr/format_version'] == JSON_FORMAT_VERSION

        coverage = {}
        for gcovr_file in gcovr_json_data['files']:
            file_path = os.path.join(os.path.abspath(options.root), gcovr_file['file'])
            file_coverage = FileCoverage(file_path)
            _lines_from_json(file_coverage, gcovr_file['lines'])
            coverage[file_path] = file_coverage

        _split_coverage_results(covdata, coverage)